The purpose of this contract is to maintain collection of blood specimens of interest to the NHLBI and, under direction of the Institute, distribute samples to the scientific community for use in research related to transfusion medicine, particularly transmission of diseases by blood or blood components, as well as research concerned with hemostatic disorders and other cardiovascular diseases. The NHLBI plans to continue to maintain this repository of specimens collected during the 1970's and now plans to add additional specimens/specimen repositories which have been or will be established during epidemiologic studies of AIDS, clinical studies of thrombolytic therapy of myocardial infarction, thrombotic purpura, and other disorders involving blood diseases, including thrombotic processes.